DVD longevity is measured by how long the data remains readable from the disc, assuming compatible devices exist that can read it: that is, how long the disc can be stored until data is lost. Numerous factors affect longevity: composition and quality of the media (recording and substrate layers), humidity and light storage conditions, the quality of the initial recording (which is sometimes a matter of mutual compatibility of media and recorder), etc.[42] According to NIST, "[a] temperature of 18°C and 40% RH [Relative Humidity] would be considered suitable for long-term storage. A lower temperature and RH is recommended for extended-term storage."[43]
According to the Optical Storage Technology Association (OSTA), "Manufacturers claim lifespans ranging from 30 to 100 years for DVD, DVD-R and DVD+R discs and up to 30 years for DVD-RW, DVD+RW and DVD-RAM." [44]
According to a NIST/LoC research project conducted in 2005-2007 using accelerated life testing, "There were fifteen DVD products tested, including five DVD-R, five DVD+R, two DVD-RW and three DVD+RW types. There were ninety samples tested for each product. [...] Overall, seven of the products tested had estimated life expectancies in ambient conditions of more than 45 years. Four products had estimated life expectancies of 30-45 years in ambient storage conditions. Two products had a estimated life expectancy of 15-30 years and two products had estimated life expectancies of less than 15 years when stored in ambient conditions." The life expectancies for 95% survival estimated in this project by type of product are tabulated below:[42]
Disc type 0-15 years 15-30 years 30-45 years over 45 years
DVD-R 20% 20% 0% 60%
DVD+R 20% 0% 40% 40%
DVD-RW 0% 0% 50% 50%
DVD+RW 0% 33.3% 33.3% 33.3%
According to the Optical Storage Technology Association (OSTA), "Manufacturers claim lifespans ranging from 30 to 100 years for DVD, DVD-R and DVD+R discs and up to 30 years for DVD-RW, DVD+RW and DVD-RAM." [44]
According to a NIST/LoC research project conducted in 2005-2007 using accelerated life testing, "There were fifteen DVD products tested, including five DVD-R, five DVD+R, two DVD-RW and three DVD+RW types. There were ninety samples tested for each product. [...] Overall, seven of the products tested had estimated life expectancies in ambient conditions of more than 45 years. Four products had estimated life expectancies of 30-45 years in ambient storage conditions. Two products had a estimated life expectancy of 15-30 years and two products had estimated life expectancies of less than 15 years when stored in ambient conditions." The life expectancies for 95% survival estimated in this project by type of product are tabulated below:[42]
Disc type 0-15 years 15-30 years 30-45 years over 45 years
DVD-R 20% 20% 0% 60%
DVD+R 20% 0% 40% 40%
DVD-RW 0% 0% 50% 50%
DVD+RW 0% 33.3% 33.3% 33.3%
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